This invention relates to an improved matrix switch board for connecting with pin plugs, hereinafter referred to as a pin board matrix. Such a pin board matrix may be advantageously employed in various electrical applications, such as electrical switching or exchange systems.
A conventionally known pin board matrix includes a laminated board with two insulative substrates, one provided thereon with a plurality of parallel conductive patterns extending in the X-direction, and the other provided thereon with a plurality of parallel conductive patterns extending in the Y-direction, substantially perpendicular to the X-direction. The laminated board has a plurality of through holes, each penetrating both of the two substrates at positions corresponding to intersections of the respective X-conductive patterns and Y-conductive patterns, so that when a short plug is inserted into a selected through hole, the X and Y-conductive patterns corresponding to the selected through hole are electrically connected to each other via the short plug.
In such a known pin board matrix the elements of the X and Y-conductive patterns are made of resilient elongated metal strips, each having a substantially U-shaped cross-section as a channel. Both side flap portions of each U-shaped strip are provided with a plurality of corresponding slits spaced in the longitudinal direction. One group of these strips also has a plurality of holes spaced in the longitudinal direction for allowing the short plug to pass therethrough and come into contact with the U-shaped strip in the other group. Thus, when the short plug is inserted into a selected through hole, it comes into resilient contact with one of the X-strip channels, passes through the hole of this strip, and then comes into resilient contact with one of the Y-strip channels.
However, in the known pin board matrix, the construction of the elements of X and Y-conductive patterns is complex and, therefore, expensive. In addition, since the pattern element is U-shaped in cross-section, the thickness of the insulative substrate, i.e., the pin board matrix, must be large to accommodate such elements.